Quaternary ammonium phosphate compound and method of preparing same

ABSTRACT

Disclosed is quaternary ammonium phosphate compound having formula (1) and which has an anticorrosive and a biocidal efffect to have a capability of preventing corrosion of various metals including corrosive metal substances, e.g. carbon steels, iron casts, stain steels, coppers, tinning steel plates or alumina and an efficient method of preparing the same. In formula (1), R 1  is a straight or a branched alkyl or aryl radical with 1 to 27 carbon atom(s) free of —OH group and may contain hereto-atoms, and both R 2  and R 3  are methyl groups or R 2  and R 3  are combined to form a heterocyclic compound with 4 to 6 of carbon atoms containing oxygen and nitrogen.

CROSS REFERENCE TO RELATED APPLICATION

This application is the national phase of PCT/KR98/00099, now WO99/12889.

This application is based on application No. 97-46517 filed in KoreanIndustrial Property Office on Sep. 10, 1997, the content of which isincorporated hereinto by reference.

BACKGROUND OF THE INVENTION

(a) Field of the Invention

The present invention relates to a novel quaternary ammonium phosphatecompound and, more particularly, to a quaternary ammonium phosphatecompound having the following formula 1 and which has an anticorrosiveand a biocidal effect and an efficient method of preparing the same.

In the above formula 1, R₁ is a straight or a branched alkyl or arylradical with 1 to 27 of carbon atom(s) free of —OH group and may containhetero-atoms, and both of R₂ and R₃ are methyl groups or R₂ and R₃ arecombined to form a heterocyclic compound with 4 to 6 of carbon atomscontaining oxygen and nitrogen.

(b) Description of the Related Arts

A quaternary ammonium halide containing a quaternary ammonium salt as aparental core, particularly, a quaternary ammonium chloride has theadvantages of having, a high biocidal effect and a low degree of surfacetension and toxicity and hence, it is often used for the purpose ofcleaning and sterilizing various household and industrial goods. And itis also widely used as an additive in wood preservatives, paints,industrial water-treating agents, cleansers and biocides because it ishighly stable.

A quaternary ammonium halide is typically prepared by using thefollowing reaction formula.

R₁R₂R₃N+R₄X→R₁R₂R₃R₄NX  Reaction formula 1

In the above reaction formula 1, R₁, R₂, R₃ and R₄ are independentlyalkyl or aryl radicals and X is a halogen compound.

Recently, quaternary ammonium chlorides, particularly,N-alkyl-N-benzyl-N-dimethyl ammonium chloride and N-dialkyl-N-dimethylammonium chloride have been the subject of many studies. They aredisclosed in U.S. Pat. Nos. 3,919,143 and 3,910,866 as polymer hardeningpromoters, disclosed in U.S. Pat. No. 5,300,635 as surfactants forseparation of RNA and disclosed in U.S. Pat. Nos. 5,290,805, 5,399,762,5,561,187 and 5,567,372 as common biocides. U.S. Pat. No. 4,929,454 andJournal of American Wood Preservativer's Association(1987) pages 331˜348by A. F. Preston disclose a technique for preserving wood byimpregnating the quaternary ammonium chloride in the wood.

U.S. Pat. No. 4,521,412 discloses iodopropargylammonium salts having apesticidal effect and a method of preparing the same, and U.S. Pat. No.5,266,567 discloses halopropargylated cyclic quaternary ammoniumcompounds and a method of preparing the same.

But all the above-described compounds have a high biocidal effect in awater system, but as they release halogen compounds such as fluorine,chlorine, bromine and iodine, they are difficult to apply to corrosivemetal substances such as carbon steels, cast irons, stain steels orcoppers. Accordingly, U.S. Pat. No. 5,438,034 (1995) discloses aquaternary ammonium carbonate and a method of preparing the same, thequaternary ammonium carbonate having the following formula 5 and whichhas no metal coupler and which can be obtained easily to be used as awood preservative. The method adopts directly a gaseous or solid carbondioxide as a carbonic acid of a reactant.

In the above formula 5, both R₁ and R₂ are alkyl groups with 8 to 12 ofcarbon atoms.

U.S. Pat. No. 5,399,762 (1995) discloses a quaternary ammonium hydroxideand a method of preparing the same, the quaternary ammonium hydroxidebeing used as a wood preservative. An aqueous solution containing 80%quaternary ammonium chloride is used as a starting material and theequilibrium of a reaction is shifted by raising a temperature to 40˜90°C. so that the quaternary ammonium hydroxide can be prepared. However,if the temperature is raised as in the above, a parental core of thequaternary ammonium salt undergoes a Hofmann elimination andrearrangement reaction when the parental core is exposed under ahigh-temperature alkaline condition so that a yellowish-brown oilyolefin and amine compounds emitting an amine ordor are formed. Thecompounds are highly hygroscopic and difficult to separate. In addition,in drying the ammonium hydroxide, a considerable quantity of thecompound is decomposed.

Moreover, all the above-described compounds have been developed anddesigned only as common biocides and except for the quaternary ammoniumhydroxide, they are limited to a structure that a leaving group of areactant are ion-bonded with the quaternary ammonium salt as an anionicconjugate of the compound

In another aspect, United Kingdom Patent No. 1,199, 015 (1968) and U.S.Pat. No. 4,252,662 (1981) disclose a method of introducing a phosphoricester as an anionic conjugate. However, this method adopts thephosphoric ester as a reactant and is applied in the field of a basematerial of a high-pressure fluid. And U.S. Pat. No. 4,716,037 disclosesa quaternary ammonium compound having an alkyl group with a terminalalcoholic group and which is used in hair conditioners for the purposeof lessening corrosion of stain steels.

SUMMARY OF THE INVENTION

It is an object of the present invention to provide a quaternaryammonium phosphate compound having the following formula 1 and which hasboth a strong anticorrosive effect on a wide range of metals andbiocidal effect to be used in corrosive metal substances such as carbonsteels, iron casts, stain steels, coppers, tinning steel plates andalumina by substituting a dihydrogen phosphate ion(H₂PO₄,) for a Cl ionfrom a quaternary ammonium chloride, and a method of preparing the same.

Particularly, a novel quaternary ammonium phosphate compound having thefollowing formula 1 is characterized in that it has an ether groupincluding an unshared electron pair to improve an anticorrosivecharacteristic greatly and to be able to form a nonoxidativeanticorrosive membrane.

A first aspect of the present invention provides a quaternary ammoniumphosphate compound having the following formula 1.

In the above formula, R₁ is a straight or a branched alkyl radical with1 to 27 carbon atoms or aryl radical with 6 to 27 carbon atoms whichdoes not contain —OH groups as substitutents on the carbon atoms, andmay contain heteroatoms in the alkyl or aryl chain; and both of R₂ andR₃ are methyl groups or R₂ and R₃ are combined to form a heterocycliccompound with 4 to 6 carbon atoms containing oxygen and nitrogen.

R₁ is preferably p-(α,α,γ,γ)-tetramethyl butyl phenoxy ethoxy ethylgroup, and R₂ and R₃ are preferably methyl groups.

And R₁ is preferably a tetradecyl group, and R₂ and R₃ are preferablymorpholinium groups having the following formula 2.

The second aspect of the present invention provides a method ofpreparing a quaternary ammonium phosphate compound having the aboveformula 1 having the step of reacting a quaternary ammonium hydroxidehaving the following formula 3 with a phosphoric acid.

In the above formula 3, R₁, R₂ and R₃ are the same as defined above.

The quaternary ammonium hydroxide is preferably prepared by reacting asolid quaternary ammonium chloride having the following formula 4 with ametal hydroxide of 1.05˜2.0 equivalents to the quaternary ammoniumchloride in a solvent containing an alcohol with 1 to 4 of carbonatom(s) at 0˜35° C.

In the above formula 4, R₁, R₂and R₃ are the same as defined above.

The third aspect of the present invention provides a composition havingan anticorrosive and a biocidal effect, containing a quaternary ammoniumphosphate compound having the above formula 1.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

A quaternary ammonium phosphate compound having the above formula 1 isprepared as follows.

Reaction formula 2

A quaternary ammonium chloride contains a N-benzyl group in a parentalcore of a quaternary ammonium salt and is preferably selected from thegroup consisting of N-dimethyl-N-[p-((α,α,γ,γ)-tetramethyl butylphenoxy]ethoxy ethyl-N-benzyl ammonium chloride, a mixture ofN-dimethyl-N-dodecyl-N-benzyl ammonium chloride,N-dimethyl-N-tetradecyl-N-benzyl ammonium chloride,N-dimethyl-N-hexadecyl-N-benzyl ammonium chloride andN-dimethyl-N-octadecyl-N-benzyl ammonium chloride, and4-benzyl-4-tetradecyl morpholinium, chloride. The metal hydroxidecontains a mono-, di- or trivalent metal, preferably a monovalent metal,and more preferably sodium or potassium.

A step for preparing the quaternary ammonium hydroxide is a typicalequilibrium reaction so that the reaction can be optimized by changingthe ratio of equivalents of reactants, solvents and conditions of thereaction. The step is preferably carried out in a solvent containing analcohol with 1 to 4 of carbon atom(s), preferably an ethanol, and morepreferably an anhydrous ethanol. When a mixture ofN-dimethyl-N-dodecyl-N-benzyl ammonium chloride,N-dimethyl-N-tetradecyl-N-benzyl ammonium chloride,N-dimethyl-N-hexadecyl-N-benzyl ammonium chloride andN-dimethyl-N-octadecyl-N-benzyl ammonium chloride is used as a startingmaterial, the content of water can be minimized and the yield can bemaximized by using the solid mixture having been crystallized with adrying method such as a lyophilization method. The metal hydroxide ispreferably 1.05˜2.0 equivalents to the quaternary ammonium chloride. Ifless 1.05 equivalents, the reaction rate is decreased and if more 2.0equivalents, decomposition reaction may occur. The reaction is performedat 0˜35° C. so that a Hofmann elimination and rearrangement reactionoccurring under a high-temperature alkaline condition can be suppressedand the reaction can be finished within 8 hours. Therefore, a filtratecontaining the quaternary ammonium hydroxide is not required to separateand can be used directly in the subsequent step so that the priorfiltrate drying step, where a considerable quantity of the quaternaryammonium hydroxide is decomposed, can be omitted.

A reaction between a quaternary ammonium hydroxide and a phosphoric acidis a neutralization reaction and even if some heat is generated, anotherside reaction is not likely to occur and therefore a separate coolingstep is not required. If the residual metal hydroxide remains in thesolution, it reacts quickly with dihydrogen phosphate ionspreferentially and can be extracted and removed easily in the form of ametal phosphate salt.

A quaternary ammonium chloride having the above formula 4 is added anddissolved at room temperature in an alcohol solvent with 1 to 4 ofcarbon atom(s). A small quantity of a metal hydroxide containing amono-, di- or trivalent metal is admixed and the solution is agitatedfor 1˜8 hour(s). As the reaction is proceeded, a metal chloride isprecipitated and the solution becomes turbid. After the reaction ends,the solution is cooled at a low temperature of about 0° C. and a whitemetal chloride is completely removed. Then a filtrate containing aquaternary ammonium hydroxide intermediate having the above formula 3 isobtained. A phosphoric acid of equivalents corresponding to those of thequaternary ammonium hydroxide intermediate and the residual metalhydroxide is added with a dropping funnel at room temperature and anacid-base reaction is proceeded. A metal phosphate is extracted andseparated with a filter. Removal of the solvent from the obtainedsolution by drying gives an oily paste or a white powdery quaternaryammonium phosphate.

A preferred embodiment of this invention will be explained withreference to the following examples.

EXAMPLES Example 1

Preparation of solid- N-dimethyl-N-[p-(α,α,γ,γ)-tetramethyl butylphenoxy]ethoxy ethyl-N-benzyl ammonium phosphate

50 ml of ethanol was added in a 100 ml round flask. 10.0 g (22 mmol) ofN-dimethyl-N-[p-(α,α,γ,γ)-tetramethyl butyl phenoxy]ethoxyethyl-N-benzyl ammonium chloride was added and dissolved at roomtemperature and then 2.21 g (33 mmol, 85%) of ground potassium hydroxidewas added. Equipped with an anhydrous calcium chloride tube, thesolution was agitated at a high rate for 6 hours. Precipitates wereformed in the solution after the elapse of time. The solution was cooledin an ice bath and filtered off. Washing of the precipitates with coldethanol gave 1.6 g of potassium chloride. 4.18 g (33 mmol) of 85%phosphoric acid was admixed with the filtrate and after 1 hour, theresidual potassium phosphate was extracted and filtered. Removal of thesolvent and drying of the solid gave 11.0 g of solidN-dimethyl-N-[p-((α,α,γ,γ)-tetramethyl butyl phenoxy]ethoxyethyl-N-benzyl ammonium phosphate.

A result of a ¹H-NMR analysis of the compound is shown as δ7.60˜7.40(m,5H), 7.26˜7.27(d,2H), 6.78(d.2H), 4.93(s,2H),4.12˜3.90(t,8H), 3.30(s,6H), 1.69(s,6H), 1,69(s,6H), 1.33(s,6H) and0.70(s,9H).

Example 2

Preparation of powdery N-dimethyl-N-[p-(α,α,γ,γ)-tetramethyl butylphenoxy]ethoxy ethyl-N-benzyl ammonium phosphate

9.68 g of solid N-dimethyl-N-[p-(α,α,γ,γ)-tetramethyl butylphenoxy]ethoxy ethyl-N-benzyl ammonium phosphate obtained in example 1was dissolved in 4 ml of boiling isopropyl alcohol and recrystallizedwith a boiling ethylacetate solvent. 7.50 g of white powderyN-dimethyl-N-[p-(α,α,γ,γ)-tetramethyl butyl phenoxy]ethoxyethyl-N-benzyl ammonium phosphate was obtained.

The melting point of the compound was 188˜192° C. and a result of a¹H-NMR analysis of the compound is shown as δ 7.60˜7.40(m,5H),7.26˜7.27(d,2H), 6.78(d.2H), 4.93(s,2H), 4.12(t,4H), 4.05(t,2H),3.30(s,6H), 1.69(s,2H), 1.33(s,6H) and 0.70(s,9H).

Example 3

Preparation of a mixture of N-dimethyl-N-dodecyl-N-benzyl ammoniumphosphate, N-dimethyl-N-tetradecyl-N-benzyl ammonium phosphate,N-dimethyl-N-hexadecyl-N-benzyl ammonium phosphate andN-dimethyl-N-octadecayl-N-benzyl ammonium phosphate

1.2 l of ethanol was added in a 2 l two-mouthed round flask. A mixtureof N-dimethyl-N-dodecyl-N-benzyl ammonium chloride,N-dimethyl-N-tetradecyl-N-benzyl ammonium chloride,N-dimethyl-N-hexadecyl-N-benzyl ammonium phosphate andN-dimethyl-N-octadecayl-N-benzyl ammonium chloride was dried in alyophilizer of −50° C. and 5 torr. 360 g (1.02 mol) of the mixture wasadded and dissolved at room temperature. 93.45 g (1.42 mol) of 85%ground potassium hydroxide was added. Equipped with an anhydrous calciumchloride tube, the solution was agitated at a high rate for 8 hours.Precipitates were formed in the solution after the elapse of time. Thesolution was cooled in an ice bath and filtered off. Washing of theprecipitates with cold ethanol gave 75 g of potassium chloride. 163.26 g(1.42 mol) of 85% phosphoric acid was admixed with the filtrate andafter 1 hour, the residual potassium phosphate was extracted andfiltered off. Removal of the solvent and admixing of an ethyl acetatesolvent gave a uniform slurry. Separation and drying of the slurry gave390 g of the mixture of N-dimethyl-N-dodecyl-N-benzyl ammoniumphosphate, N-dimethyl-N-tetradecyl-N-benzyl ammonium phosphate,N-dimethyl-N-hexadecyl-N-benzyl ammonium phosphate andN-dimethyl-N-octadecayl-N-benzyl ammonium phosphate.

A result of a ¹H-NMR analysis of the compound is shown as δ7.48˜7.44(m,5H), 4.52(s,2H), 3.11 (s,6H), 3.05(t,2H) and 0.87(t,3H).

Example 4

Preparation of 4-benzyl-4-tetradecyl morpholinium ammonium phosphate.

5 ml of ethanol was added in a 50 ml round flask. 4.26 g (10 mmol) of4-benzyl-4-tetradecyl morpholinium ammonium chloride was added anddissolved at room temperature. 420 mg (10.5 mmol) of ground potassiumhydroxide was added. Equipped with an anhydrous calcium chloride tube,the solution was agitated at a high rate for 8 hours. Precipitates wereformed in the solution with the elapse of time. The solution was cooledin an ice bath and filtered off. Washing of the precipitates with coldethanol gave 550 mg of sodium chloride. 1.21 g (10.5 mmol) of 85%phosphoric acid was admixed with the filtrate and after 1 hour, theresidual potassium phosphate was extracted and filtered off. Removal ofthe solvent and admixing of 20 ml of an ethyl acetate solvent gave auniform slurry. Drying of the slurry gave 4.15 g of yellowish-brownsolid 4-benzyl-4-tetradecyl morpholinium ammonium phosphate

A result of a ¹H-NMR analysis of the compound is shown as δ 7.53(m,5H),4.68(s,2H), 4.10(t, 4H), 4.00(t,2H), 3.39(t, 4H), 1.37˜1.29(m,22H),1.38(m,2H) and 0.88(t,3H).

Comparative example 1

Preparation of N-dimethyl-N-[p-N-[p-((α,α,γ,γ)-tetramethyl butylphenoxy]ethoxy ethyl-N-benzyl ammonium phosphate.

Example 1 was repeated except that the solution was agitated for 30minutes at room temperature and that after the reaction with thephosphoric acid, the solvent was removed and an ethyl acetate solventwas added to obtain a uniform slurry. Filtration and drying of theslurry gave N-dimethyl-N-[p-N-[p-(α,α,γ,γ)-tetramethyl butylphenoxy]ethoxy ethyl-N-benzyl ammonium phosphate.

Comparative example 2

Preparation of 4-benzyl-4-tetradecyl morpholinium ammonium phosphate.

Example 4 was repeated except that the reaction was carried out in anice bath containing a saturated sodium chloride solution. 310 mg ofpotassium chloride was formed as an intermediate and4-benzyl-4-tetradecyl morpholinium ammonium phosphate was finallyobtained.

Comparative example 3

Preparation of a mixture of N-dimethyl-N-dodecyl-N-benzyl ammoniumphosphate, N-dimethyl-N-tetradecyl-N-benzyl ammonium phosphate,N-dimethyl-N-hexadecyl-N-benzyl ammonium phosphate andN-dimethyl-N-octadecayl-N-benzyl ammonium phosphate

Example 3 was repeated except that the quaternary ammonium chlorideswere not lyophilized and used in the form of a 50% aqueous solution. Amixture of N-dimethyl-N-dodecyl-N-benzyl ammonium phosphate,N-dimethyl-N-tetradecyl-N-benzyl ammonium phosphate,N-dimethyl-N-hexadecyl-N-benzyl ammonium phosphate andN-dimethyl-N-octadecayl-N-benzyl ammonium phosphate was obtained.

The yields of the examples and the comparative examples are shown belowin table 1.

TABLE 1 Yield(%) Example 1 99 Example 2 77.5 Example 3 93.8 Example 4 88Comparative example 1 68 Comparative example 2 49 Comparative example 345

As shown in table 1, the preparation method of the present inventioneasily obtains a quaternary ammonium phosphate in a high yield.

Anticorrosive Effect Test

This test was carried out for the purpose of measuring an anticorrosiveeffect of the compounds obtained from examples 1, 3 and 4. An anhydrouscalcium chloride and magnesium sulfate 7 hydrates were mixed in 1 l ofpure water to formulate 15 ppm of magnesium hardness. A test materialwas added to 20 ppm and the final pH was adjusted to 8.5. A water tankat 40° C. was used, 100 cc of air was supplied per minute and thesolution was agitated at 150 rpm. A metal test piece used were carbonsteel (c-1020), copper, cast iron, tinning steel plate of which thesurface areas were respectively 0.21 g/dm², 0.20 g/dm², 0.22 g/dm², and0.17 g/dm². The rate of corrosion was analyzed from the weight loss ofthe test piece after 42 hours and the measuring unit was mpy(mils peryear).

Biocidal Effect Test

This test was carried out for the purpose of measuring a biocidal effectof the compounds obtained from examples 1, 3 and 4. A test material wasdiluted using a serial dilution method in a 96-multiwelled plate. 10⁴cfu/ml of microbes were inoculated in the diluted solution. After themicrobes were cultivated for 48 hours at 30° C., MIC (Minimal InhibitionConcentration of microorganisms) was visually observed to decide whetheror not microbial growth occurred from the turbidity. The growth mediumwas nutrient broth, DIFCO, and the strains used were as follows.

Bacteria

Enterobacter aerogenes ATCC 13048, Escherichia coli ATCC 11229,Micrococcus luteus ATCC 9431, Pseudomonas aeruginosa ATCC 15442,Shigella sonnei ATCC 9290, Staphylococcus epidermis ATCC 155,Staphylococcus aureus ATCC 6538 and Bacillus subtilis ATCC 6984.

Yeasts

Candida albicans ATCC 10231, Rhodotorula rubra ATCC 9449, Cryptococcusneoformans ATCC 34144 and Saccharomyces cerevisiae ATCC 9763.

Fungi

Penicillium citrinum ATCC 98404, Trichoderma viridae ATCC 1287, Rhizopusoryzae ATCC 10404 and Aspergillus niger ATCC 9642.

Test results are shown below in table 2.

TABLE 2 Anticorrosive effect (mpy) Minimal Inhibition carbon casttinning Concentration (ppm) steel iron copper steel Bacteria yeastsfungi example 1 4.5 1.3 0.1 0.1 6.3˜12.5   6.3˜12.5 25˜100 example 3 3.74.6 0.2 0.3 12.5˜25   12.5˜25 25˜100 example 4 5.1 0.8 0.1 0.1 6.3˜12.512.5˜25 25˜100 A 7.2 6.5 0.5 0.5 12.5˜25   12.5˜25 25˜100 B 6.8 7.1 0.40.7 6.3˜12.5  6.3˜25 25˜100 C 10.5 11.1 0.3 0.6 6.3˜12.5 12.5˜50 25˜100D 18.7 13.9 0.1 0.3 — — — E 7.6 5.1 0.2 0.3 — — — F 33.0 25.5 0.7 1.9 —— — A: N-dimethyl-N-[p-(α,α,γ,γ)-tetramethyl butyl phenoxy]ethoxyethyl-N-benzyl chloride B: 4-benzyl-4-tetradecyl morpholinium ammoniumchloride C: a mixture of N-dimethyl-N-dodecyl-N-benzyl ammoniumchloride, N-dimethyl-N-tetradecyl-N-benzyl ammonium chloride,N-dimethyl-N-hexadecyl-N-benzyl ammonium chloride andN-dimethyl-N-octadecyl-N-benzyl ammonium chloride D: sodium dihydrogenphosphate (NaH₂PO₄.12H₂O) E: N-dimethyl-N-cetyl-N-hydroxyethyl ammoniumphosphate F: Blank (no compound contained)

As shown in table 2, the quaternary ammonium phosphate compounds of thepresent invention have a high anticorrosive effect on carbon steels,cast irons, coppers and tinning steel plates. This results from asynergic effect between an ether bond of an unshared electron pair in analkyl group of a parental core of, a quaternary ammonium and phosphateof an anion. The compound also has a high anticorrosive effect.

The present invention provides a compound which has an anticorrosiveeffect on a wide range of corrosive metal substances e.g. carbon steels,iron casts, stain steels, coppers., tinning steel plates and alumina andwhich has a biocidal effect, a cleaning effect and a low toxicity. Thecompound is useful where a strong biocidal effect is required, where acleaning effect is required and where low toxicity and where low skinirritability is required and when applied to equipment, devices orapparatus made of corrosive substances. Moreover, the compound hasproperties to allow performance of a substitution reaction, and provideshigh purity and low toxicity so that it can be easily used on acommercial scale.

While the present invention has been described in detail with referenceto the preferred embodiments, those skilled in the art will appreciatethat various modifications and substitutions can be made thereto withoutdeparting from the spirit and scope of the present invention as setforth in the appended claims.

What is claimed is:
 1. A quaternary ammonium phosphate compound havingan anticorrosive and a biocidal effect, the compound having the formula

wherein R₁ is a p-(α,α,γ,γ)-tetramethyl butyl phenoxy ethoxy ethylgroup, and R₂ and R₃ are methyl groups.
 2. A quaternary ammoniumphosphate compound having an anticorrosive and a biocidal effect, thecompound having the formula

wherein R₁ is a tetradecyl group, and R₂ and R₃ together form amorpholinium group having the following formula


3. A method of preparing a quaternary ammonium phosphate compound havingthe formula

wherein R₁ is a straight or branched alkyl radical with 1 to 27 carbonatoms or aryl radical with 6 to 27 carbon atoms, which does not contain—OH groups as substitutents on the carbon atoms, and may containheteroatoms in the alkyl or aryl chain; and both of R₂ and R₃ are methylgroups or R₂ and R₃ together form a morpholinium group having thefollowing formula,

 the method comprising the steps of: (a) reacting a quaternary ammoniumchloride having the following formula

with 1.05 to 2.0 equivalents of metal hydroxide per equivalent of thequaternary ammonium chloride in a solvent containing an alcohol with 1to 4 carbon atom(s) at 0 to 35° C., wherein R₁, R₂, and R₃ are the sameas defined above, to obtain a quaternary ammonium hydroxide having thefollowing formula

wherein R₁, R₂ and R₃ are the same as defined above; and (b) reactingthe quaternary ammonium hydroxide with phosphoric acid at a temperaturebetween about 0° C. and about 19° C. to obtain the quaternary ammoniumphosphate compound.
 4. A composition having an anticorrosive and abiocidal effect comprising: the quaternary ammonium phosphate compoundof claim
 1. 5. A composition having an anticorrosive and a biocidaleffect comprising: the quaternary ammonium phosphate compound of claim2.